.page-about {
  padding-block: clamp(20px, 4vw, 48px) clamp(60px, 9vw, 116px);
}

.page-about .breadcrumbs {
  margin-bottom: clamp(18px, 3vw, 32px);
}

/* ---------- 开篇 ---------- */

.page-about .about-open {
  max-width: 68ch;
  margin-bottom: clamp(28px, 4.6vw, 54px);
}

.page-about .about-open h1 {
  margin: 12px 0 20px;
  font-size: clamp(31px, 6.6vw, 66px);
  line-height: 1.04;
  letter-spacing: -0.022em;
  font-weight: 800;
  color: var(--scoreboard-ivory);
  text-wrap: balance;
}

.page-about .about-lede {
  max-width: 64ch;
  margin: 0 0 clamp(24px, 3.4vw, 36px);
  font-size: clamp(15px, 1.7vw, 18px);
  line-height: 1.8;
  color: var(--ink-mute);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0 0 clamp(18px, 2.6vw, 26px);
  padding: 0;
  background: var(--net-line);
  border: 1px solid var(--net-line);
}

.page-about .about-stats > .stat {
  min-width: 0;
  padding: 16px 14px 18px;
  background: var(--turf-shadow);
}

.page-about .about-stats dt,
.page-about .about-stats dd {
  margin: 0;
}

.page-about .about-stats .stat-label {
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--cyan-soft);
  text-transform: uppercase;
}

.page-about .about-stats .stat-value {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: clamp(25px, 4.4vw, 40px);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.01em;
  color: var(--amber-signal);
  word-break: break-word;
}

.page-about .about-stats .stat-value--cyan {
  color: var(--floodlight-cyan);
}

.page-about .about-readout {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 6px 12px;
  border: 1px solid var(--line-soft);
  background: var(--cyan-veil);
  color: var(--cyan-soft);
}

/* ---------- 首屏图 ---------- */

.page-about .about-hero {
  margin: 0 0 clamp(34px, 5vw, 62px);
}

/* ---------- 纵向赛道 ---------- */

.page-about .about-track {
  --about-rail-gap: 22px;
  --about-rail-x: 5px;
  position: relative;
  padding-left: var(--about-rail-gap);
}

.page-about .about-track::before {
  content: "";
  position: absolute;
  left: var(--about-rail-x);
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, transparent, var(--net-line) 5%, var(--net-line) 95%, transparent);
  pointer-events: none;
}

.page-about .about-panel {
  position: relative;
  margin-bottom: clamp(20px, 3vw, 34px);
  padding: clamp(20px, 3.4vw, 44px);
  background: var(--turf-shadow);
  border: 1px solid var(--net-line);
  transition: border-color 0.34s var(--ease), box-shadow 0.34s var(--ease);
}

.page-about .about-panel:last-of-type {
  margin-bottom: 0;
}

.page-about .about-panel::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 0;
  bottom: 0;
  width: 3px;
  background: linear-gradient(180deg, var(--net-line), transparent 72%);
  transition: background 0.34s var(--ease);
  pointer-events: none;
}

.page-about .about-panel.is-current {
  border-color: rgba(35, 240, 199, 0.42);
  box-shadow: inset 0 0 0 1px rgba(35, 240, 199, 0.1), 0 0 48px -22px rgba(35, 240, 199, 0.7);
}

.page-about .about-panel.is-current::before {
  background: linear-gradient(180deg, var(--floodlight-cyan), var(--amber-signal));
}

.page-about .about-panel .panel-head {
  max-width: 68ch;
}

.page-about .about-panel .panel-title {
  margin: 8px 0 0;
  font-size: clamp(22px, 3.4vw, 38px);
  line-height: 1.16;
  letter-spacing: -0.014em;
  font-weight: 800;
}

.page-about .about-panel .panel-meta {
  margin: 14px 0 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ink-faint);
}

/* ---------- 正文与数据卡 ---------- */

.page-about .about-prose {
  max-width: 66ch;
  margin-top: clamp(16px, 2.2vw, 24px);
}

.page-about .about-prose p {
  margin: 0 0 1.05em;
  font-size: 16px;
  line-height: 1.82;
  color: var(--ink-mute);
}

.page-about .about-prose p:last-child {
  margin-bottom: 0;
}

.page-about .about-note {
  margin-top: clamp(18px, 2.6vw, 28px);
  padding: 16px 20px;
  background: var(--cyan-veil);
  border-left: 2px solid var(--floodlight-cyan);
}

.page-about .about-note .data-card-head {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--cyan-soft);
}

.page-about .about-note .data-card-value {
  margin: 8px 0 0;
  font-family: var(--font-mono);
  font-size: clamp(20px, 3vw, 28px);
  font-weight: 700;
  color: var(--scoreboard-ivory);
  letter-spacing: -0.01em;
}

.page-about .about-note-text {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-faint);
}

/* ---------- 四条内容线 ---------- */

.page-about .about-lines {
  list-style: none;
  margin: clamp(20px, 3vw, 32px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--net-line);
  border: 1px solid var(--net-line);
}

.page-about .about-line {
  padding: clamp(18px, 2.6vw, 28px);
  background: var(--deep-pitch);
  border-left: 2px solid var(--emerald-mid);
}

.page-about .about-line:nth-child(1) {
  border-left-color: var(--floodlight-cyan);
}

.page-about .about-line:nth-child(2) {
  border-left-color: var(--amber-signal);
}

.page-about .about-line:nth-child(3) {
  border-left-color: var(--emerald-mid);
}

.page-about .about-line:nth-child(4) {
  border-left-color: var(--cyan-soft);
}

.page-about .about-line-no {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--ink-faint);
}

.page-about .about-line-title {
  margin: 0 0 8px;
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 700;
  letter-spacing: -0.008em;
  color: var(--scoreboard-ivory);
}

.page-about .about-line-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--ink-mute);
}

/* ---------- 折线示意 ---------- */

.page-about .about-chart {
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  padding-top: clamp(16px, 2.4vw, 24px);
  border-top: 1px solid var(--net-line);
}

.page-about .about-chart figcaption {
  margin-bottom: 14px;
  color: var(--cyan-soft);
}

.page-about .about-chart svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-chart-grid {
  fill: none;
  stroke: var(--net-line);
  stroke-width: 1;
  stroke-dasharray: 2 7;
}

.page-about .about-chart-line {
  fill: none;
  stroke: var(--floodlight-cyan);
  stroke-width: 2;
  stroke-linejoin: round;
  stroke-linecap: round;
}

.page-about .about-chart-dot {
  fill: var(--deep-pitch);
  stroke: var(--amber-signal);
  stroke-width: 2;
}

.page-about .about-chart-axis {
  fill: rgba(233, 243, 238, 0.44);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
}

/* ---------- 数据作业 ---------- */

.page-about .about-split {
  display: grid;
  gap: clamp(22px, 3.2vw, 38px);
}

.page-about .about-split-main {
  min-width: 0;
}

.page-about .about-big {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  margin: clamp(16px, 2.4vw, 24px) 0 0;
  padding-top: clamp(14px, 2vw, 20px);
  border-top: 1px solid var(--net-line);
}

.page-about .about-big-num {
  font-family: var(--font-mono);
  font-size: clamp(34px, 6vw, 56px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.015em;
  color: var(--amber-signal);
}

.page-about .about-big-unit {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--ink-faint);
}

.page-about .about-media {
  margin: 0;
}

.page-about .about-groups {
  list-style: none;
  margin: clamp(22px, 3.2vw, 34px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--net-line);
  border: 1px solid var(--net-line);
}

.page-about .about-group {
  min-width: 0;
  padding: 18px 18px 20px;
  background: var(--deep-pitch);
}

.page-about .about-group-name {
  display: block;
  margin-bottom: 10px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--scoreboard-ivory);
}

.page-about .about-group-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.4vw, 32px);
  font-weight: 700;
  line-height: 1;
  color: var(--floodlight-cyan);
}

.page-about .about-group-unit {
  margin-left: 5px;
  font-family: var(--font-sans);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--ink-faint);
}

.page-about .about-group-text {
  margin: 12px 0 0;
  font-size: 13px;
  line-height: 1.72;
  color: var(--ink-mute);
}

/* ---------- 为谁而做 ---------- */

.page-about .about-audience {
  list-style: none;
  margin: clamp(20px, 3vw, 32px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(14px, 2vw, 20px);
}

.page-about .about-aud {
  padding: clamp(18px, 2.4vw, 26px);
  border: 1px solid var(--net-line);
  background: linear-gradient(158deg, rgba(35, 240, 199, 0.07), rgba(10, 31, 26, 0) 58%);
}

.page-about .about-aud-tag {
  display: inline-block;
  margin-bottom: 12px;
  padding: 4px 10px;
  border: 1px solid var(--line-soft);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--amber-signal);
}

.page-about .about-aud-title {
  margin: 0 0 10px;
  font-size: clamp(16px, 1.9vw, 19px);
  font-weight: 700;
  line-height: 1.4;
  color: var(--scoreboard-ivory);
}

.page-about .about-aud-text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--ink-mute);
}

/* ---------- 昆明节点 ---------- */

.page-about .about-node-panel {
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  min-height: 340px;
}

.page-about .about-node-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  max-width: none;
  object-fit: cover;
  opacity: 0.36;
  filter: saturate(0.72) contrast(1.06);
}

.page-about .about-node-panel::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(180deg, rgba(10, 31, 26, 0.58), rgba(10, 31, 26, 0.95));
  pointer-events: none;
}

.page-about .about-node-panel > *:not(.about-node-bg) {
  position: relative;
  z-index: 2;
}

.page-about .about-node-panel::before {
  z-index: 3;
}

/* ---------- 版本节点折叠 ---------- */

.page-about .about-steps {
  margin-top: clamp(20px, 3vw, 32px);
  border-top: 1px solid var(--net-line);
}

.page-about .about-step {
  border-bottom: 1px solid var(--net-line);
}

.page-about .about-step-btn {
  display: flex;
  align-items: baseline;
  gap: 14px;
  width: 100%;
  padding: 18px 2px;
  background: none;
  border: 0;
  text-align: left;
  cursor: pointer;
  color: var(--scoreboard-ivory);
  font-family: inherit;
}

.page-about .about-step-btn:hover .about-step-title,
.page-about .about-step-btn:focus-visible .about-step-title {
  color: var(--floodlight-cyan);
}

.page-about .about-step-time {
  flex: 0 0 auto;
  min-width: 88px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--floodlight-cyan);
}

.page-about .about-step-title {
  flex: 1 1 auto;
  font-size: clamp(15px, 1.8vw, 18px);
  font-weight: 700;
  line-height: 1.5;
  transition: color 0.2s var(--ease);
}

.page-about .about-step .disclosure-icon {
  flex: 0 0 auto;
  align-self: center;
}

.page-about .about-step-body {
  max-width: 68ch;
  padding: 0 2px 22px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-mute);
}

/* ---------- 收尾 ---------- */

.page-about .about-cta {
  margin-top: clamp(28px, 4.4vw, 56px);
  padding: clamp(24px, 4vw, 48px);
}

.page-about .about-cta .panel-title {
  margin: 8px 0 0;
  font-size: clamp(22px, 3.4vw, 36px);
  line-height: 1.18;
  letter-spacing: -0.014em;
  font-weight: 800;
}

.page-about .about-cta-text {
  max-width: 58ch;
  margin: 16px 0 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(233, 243, 238, 0.78);
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 2.8vw, 30px);
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-lines {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-audience {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .about-track {
    --about-rail-gap: 46px;
    --about-rail-x: 11px;
  }

  .page-about .about-split {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }

  .page-about .about-groups {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-node-panel {
    min-height: 420px;
  }

  .page-about .about-step-btn {
    padding: 22px 2px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-panel,
  .page-about .about-panel::before,
  .page-about .about-step-title {
    transition: none;
  }
}